This invention relates to a pharmaceutical composition for the treatment of cutaneous disorders or disruptions characterized by skin inflammation and/or hyperproliferative activity in the epidermis. More specifically, the invention comprises treatment of such disorders by concurrent topical application to the affected area of an anti-inflammatory steroidal drug and of a selected non-steroidal anti-inflammatory drug, each in a suitable vehicle. In one preferred embodiment, the invention comprises the novel combination of an anti-inflammatory steroidal drug with a selected non-steroidal anti-inflammatory drug in a suitable vehicle for topical use.
There are many steroidal drugs suitable for treating particular responsive dermatological disorders. Many of these steroids must be used systemically. Others exhibit good activity topically in a suitable vehicle. While some steroidal anti-inflammatories are effective both systemically and topically, there is not ordinarily any predictable relationship between systemic and topical activity of a drug, particularly an anti-inflammatory steroidal drug. In addition to having a broad range of applicable biological activities (e.g., cell membrane stabilization, vasoconstrictor activity, antimitotic effect, suppression of DNA and protein synthesis, etc.), the steroids often exhibit undesired local and systemic side effects when used for prolonged periods. These may be manifested in the form of local skin atrophy, or in adrenal atrophy in the most severe case. Furthermore, a reduction in host defense mechanisms to infection may accompany their use.
Beyond the potential undesired side effects, steroids do not interact with the complete biological spectrum of inflammation. For example, ultraviolet (UV) light induced erythema is not amenable to treatment by steroidal anti-inflammatories. UV-induced early changes in skin such as vasodilatation are related to the conversion of arachidonic acid to E prostaglandins or to inermediate forms such as HETE (12L-hydroxy-5,8,10,14-eicosatetraenoic acid) or the endoperoxides which are vasoactive and are believed to have cutaneous activity, such as triggering hyperproliferative epidermal activity. See, for example, Bem, J. L. and Greaves, M. W. 1974 Prostaglandin E.sub.1 effects on epidermal cell growth "in vitro." Arch. Derm. Forsch. 251:35-41; Snyder, D. S. and Eaglstein, W. H. 1974 Topical indomethacin and sunburn. Brit. J. Derm. 90:91-93; Snyder, D. S. and Eaglstein, W. H. 1974 Intradermal anti-prostaglandin agents and sunburn. J. Invest. Derm. 62:47-50; and Goldyne, M. E. at al. 1973 Prostaglandin activity in human cutaneous inflammation: Detection by radio-immunoassay. Prostaglandins 4:737-749. See also Hsia, S. L., Ziboh, V. A. and Snyder, D. S. 1974 Naturally occurring and synthetic inhibitors of prostaglandin synthetase of the skin. Prostaglandin Synthetase Inhibitors 353-361. Although it is not understood completely, it is thought that these effects related to prostaglandin biosynthesis are important components of many dermatopathologies, so a drug which will interfere with this biosynthesis should be useful in the clinical improvement of the disease.
There are many non-steroidal compounds or agents which also have anti-inflammatory effects. Many of these are believed to act by blocking the prostaglandin synthetase complex of enzymes that are present in normal skin and are necessary for the biosynthetic processes descibed above. Furthermore, as a general rule, these drugs are relatively free of unwanted side effects. Examples of such non-steroidal anti-inflammatory compounds include aspirin, indomethacin, suprofen, cliprofen and ethyl 5-p-chlorobenzoyl-1,4-dimethylpyrrole-2-acetate.